scholarly journals Probabilistic risk assessment of solar particle events considering the cost of countermeasures to reduce the aviation radiation dose

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Moe Fujita ◽  
Tatsuhiko Sato ◽  
Susumu Saito ◽  
Yosuke Yamashiki
Keyword(s):  
Dose Rate ◽  
Cost Estimation ◽  
Ice Cores ◽  
Cosmic Ray ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Radiological Protection ◽  
Long Distance ◽  
Solar Particle Events ◽  
The Cost

AbstractCosmic-ray exposure to flight crews and passengers, which is called aviation radiation exposure, is an important topic in radiological protection, particularly for solar energetic particles (SEP). We therefore assessed the risks associated with the countermeasure costs to reduce SEP doses and dose rates for eight flight routes during five ground level enhancements (GLE). A four-dimensional dose-rate database developed by the Warning System for Aviation Exposure to Solar Energetic Particles, WASAVIES, was employed in the SEP dose evaluation. As for the cost estimation, we considered two countermeasures; one is the cancellation of the flight, and the other is the reduction of flight altitudes. Then, we estimated the annual occurrence frequency of significant GLE events that would bring the maximum flight route dose and dose rate over 1.0 mSv and 80 μSv/h, respectively, based on past records of GLE as well as historically large events observed by the cosmogenic nuclide concentrations in tree rings and ice cores. Our calculations suggest that GLE events of a magnitude sufficient to exceed the above dose and dose rate thresholds, requiring a change in flight conditions, occur once every 47 and 17 years, respectively, and their conservatively-estimated annual risks associated with the countermeasure costs are up to around 1.5 thousand USD in the cases of daily-operated long-distance flights.

scholarly journals Ulysses COSPIN observations of cosmic rays and solar energetic particles from the South Pole to the North Pole of the Sun during solar maximum

2003 ◽  
Vol 21 (6) ◽  
pp. 1217-1228 ◽  
Author(s):  
R. B. McKibben ◽  
J. J. Connell ◽  
C. Lopate ◽  
M. Zhang ◽  
J. D. Anglin ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Solar Maximum ◽  
Cosmic Ray ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Polar Regions ◽  
The Sun ◽  
The South ◽  
The North ◽  
Inner Heliosphere

Abstract. In 2000–2001 Ulysses passed from the south to the north polar regions of the Sun in the inner heliosphere, providing a snapshot of the latitudinal structure of cosmic ray modulation and solar energetic particle populations during a period near solar maximum.  Observations from the COSPIN suite of energetic charged particle telescopes show that latitude variations in the cosmic ray intensity in the inner heliosphere are nearly non-existent near solar maximum, whereas small but clear latitude gradients were observed during the similar phase of Ulysses’ orbit near the 1994–95 solar minimum. At proton energies above ~10 MeV and extending up to >70 MeV, the intensities are often dominated by Solar Energetic Particles (SEPs) accelerated near the Sun in association with intense solar flares and large Coronal Mass Ejections (CMEs). At lower energies the particle intensities are almost constantly enhanced above background, most likely as a result of a mix of SEPs and particles accelerated by interplanetary shocks. Simultaneous high-latitude Ulysses and near-Earth observations show that most events that produce large flux increases near Earth also produce flux increases at Ulysses, even at the highest latitudes attained. Particle anisotropies during particle onsets at Ulysses are typically directed outwards from the Sun, suggesting either acceleration extending to high latitudes or efficient cross-field propagation somewhere inside the orbit of Ulysses. Both cosmic ray and SEP observations are consistent with highly efficient transport of energetic charged particles between the equatorial and polar regions and across the mean interplanetary magnetic fields in the inner heliosphere.Key words. Interplanetary physics (cosmic rays) – Solar physics, astrophysics and astronomy (energetic particles; flares and mass ejections)

scholarly journals On the Turbulent Reduction of Drifts for Solar Energetic Particles

2021 ◽  
Vol 922 (2) ◽  
pp. 200
Author(s):  
J. P. van den Berg ◽  
N. E. Engelbrecht ◽  
N. Wijsen ◽  
R. D. Strauss
Keyword(s):  
Pitch Angle ◽  
Cosmic Ray ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Particle Distributions ◽  
Magnetic Turbulence ◽  
Field Diffusion ◽  
Background Magnetic Field ◽  
Perpendicular Diffusion ◽  
Inner Heliosphere

Abstract Particle drifts perpendicular to the background magnetic field have been proposed by some authors as an explanation for the very efficient perpendicular transport of solar energetic particles (SEPs). This process, however, competes with perpendicular diffusion caused by magnetic turbulence, which can also disrupt the drift patterns and reduce the magnitude of drift effects. The latter phenomenon is well known in cosmic-ray studies, but not yet considered in SEP models. Additionally, SEP models that do not include drifts, especially for electrons, use turbulent drift reduction as a justification of this omission, without critically evaluating or testing this assumption. This article presents the first theoretical step for a theory of drift suppression in SEP transport. This is done by deriving the turbulence-dependent drift reduction function with a pitch-angle dependence, as is applicable for anisotropic particle distributions, and by investigating to what extent drifts will be reduced in the inner heliosphere for realistic turbulence conditions and different pitch-angle dependencies of the perpendicular diffusion coefficient. The influence of the derived turbulent drift reduction factors on the transport of SEPs are tested, using a state-of-the-art SEP transport code, for several expressions of theoretically derived perpendicular diffusion coefficients. It is found, for realistic turbulence conditions in the inner heliosphere, that cross-field diffusion will have the largest influence on the perpendicular transport of SEPs, as opposed to particle drifts.

Correlation analysis of solar energetic particles and secondary cosmic ray flux

2021 ◽  
Vol 75 (6) ◽  
Author(s):  
Nikola Veselinović ◽  
Mihailo Savić ◽  
Aleksandar Dragić ◽  
Dimitrije Maletić ◽  
Radomir Banjanac ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Cosmic Ray ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Cosmic Ray Flux

scholarly journals Current status and possible extension of the global neutron monitor network

2020 ◽  
Vol 10 ◽  
pp. 17
Author(s):  
Alexander Mishev ◽  
Ilya Usoskin
Keyword(s):  
Space Weather ◽  
Neutron Monitor ◽  
Cosmic Ray ◽  
Ground Level ◽  
Solar Proton ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Current Status ◽  
Flight Altitude ◽  
Ground Level Enhancements

The global neutron monitor network has been successfully used over several decades to study cosmic ray variations and fluxes of energetic solar particles. Nowadays, it is used also for space weather purposes, e.g. alerts and assessment of the exposure to radiation. Here, we present the current status of the global neutron monitor network. We discuss the ability of the global neutron monitor network to study solar energetic particles, specifically during large ground level enhancements. We demonstrate as an example, the derived solar proton characteristics during ground level enhancements GLE #5 and the resulting effective dose over the globe at a typical commercial jet flight altitude of 40 kft (≈12,200 m) above sea level. We present a plan for improvement of space weather services and applications of the global neutron monitor network, specifically for studies related to solar energetic particles, namely an extension of the existing network with several new monitors. We discuss the ability of the optimized global neutron monitor network to study various populations of solar energetic particles and to provide reliable space weather services.

scholarly journals About the Altitude Profile of the Atmospheric Cut-Off of Cosmic Rays: New Revised Assessment

Solar Physics ◽  
2021 ◽  
Vol 296 (8) ◽  
Author(s):  
Alexander Mishev ◽  
Stepan Poluianov
Keyword(s):  
Cosmic Rays ◽  
Neutron Monitor ◽  
Cosmic Ray ◽  
High Energy ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Global Network ◽  
Joint Analysis ◽  
Cosmic Ray Intensity ◽  
Altitude Profile

AbstractCosmic rays, high-energy subatomic particles of extraterrestrial origin, are systematically measured by space-borne and ground-based instruments. A specific interest is paid to high-energy ions accelerated during solar eruptions, so-called solar energetic particles. In order to build a comprehensive picture of their nature, it is important to fill the gap and inter-calibrate ground-based and space-borne instruments. Here, we focus on ground-based detectors, specifically neutron monitors, which form a global network and provide continuous recording of cosmic ray intensity and its variability, used also to register relativistic solar energetic particles. The count rate of each neutron monitor is determined by the geomagnetic and atmospheric cut-offs, both being functions of the location. Here, on the basis of Monte Carlo simulations with the PLANETOCOSMICS code and by the employment of a new verified neutron monitor yield function, we assessed the atmospheric cut-off as a function of the altitude, as well as for specific stations located in the polar region. The assessed in this study altitude profile of the atmospheric cut-off for primary cosmic rays builds the basis for the joint analysis of strong solar proton events with different instruments and allows one to clarify recent definitions and related discussions about the new sub-class of events, so-called sub-ground-level enhancements (sub-GLEs).

scholarly journals Frequent Flyer Cost Estimation

2022 ◽  
Vol 19 (4) ◽  
pp. 74-80
Author(s):  
V. E. Zhukov
Keyword(s):  
Cost Estimation ◽  
Indirect Costs ◽  
Air Transportation ◽  
Marketing Activity ◽  
Long Distance ◽  
Frequent Flyer ◽  
Regional Markets ◽  
The Subject ◽  
The Cost ◽  
Program Point

The marketing activity of a modern airline is quite diverse. Under the conditions of an oligopoly, airlines develop their business in competition for a passenger.In modern conditions in Russia, the use of dumping methods of the early 1990s is very ineffective. There are no weak airlines left on the long-distance air transportation market, and in regional markets large companies lose to small regional carriers due to the high cost of performing flights on large-capacity aircrafts of the airline’s fleet.Generally, non-price methods of competition come out on top. Flexible tariff policy, advertising, and high service in servicing passengers remain leading traditional methods of competing for a passenger.This article is devoted to the study of another marketing method for attracting passengers, or rather retaining passengers on the airline’s flights, which is development of bonus programs, frequent flyer programs. PJSC Russian Airlines (Aeroflot) was chosen as the object for the study. The subject of the research is the «Aeroflot Bonus» program.The objective of the study is to study the cost of the program. For research purposes, this is the value of the frequent flyer program point. The problem proposed to be solved is to determine the amount of expenses for implementation of the bonus program of frequent flyers. When solving the problem in its staging part, the assessment is not limited to direct costs associated with the costs of marketing efforts in the form of costs for organising a special advertising department, issuing bonus cards, software, and wages. The estimation refers also to indirect costs in the form of unreceived proceeds from free bonus tickets. Besides, a rough estimate has been made of the airline’s hidden costs due to an unpaid seat on the plane. The study conclusions indicate that hidden costs will be taken into account in calculating the cost of a flight and the bonus program has a right to exist.

Assessing the Predictability of Solar Energetic Particles with the Use of Machine Learning Techniques

Solar Physics ◽  
2021 ◽  
Vol 296 (7) ◽  
Author(s):  
E. Lavasa ◽  
G. Giannopoulos ◽  
A. Papaioannou ◽  
A. Anastasiadis ◽  
I. A. Daglis ◽  
...  
Keyword(s):  
Machine Learning ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Machine Learning Techniques ◽  
Learning Techniques

scholarly journals Methodology for the Concept Design of Locally Reinforced Composites

2021 ◽  
Vol 11 (16) ◽  
pp. 7246
Author(s):  
Julius Moritz Berges ◽  
Georg Jacobs ◽  
Sebastian Stein ◽  
Jonathan Sprehe
Keyword(s):  
Cost Estimation ◽  
Structural Design ◽  
Early Stage ◽  
Parameter Study ◽  
Great Effort ◽  
Concept Design ◽  
Cost Weight ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics ◽  
The Cost

Locally load-optimized fiber-based composites, the so-called tailored textiles (TT), offer the potential to reduce weight and cost compared to conventional fiber-reinforced plastics (FRP). However, the design of TT has a higher complexity compared to FRP. Current approaches, focusing on solving this complexity for multiple objectives (cost, weight, stiffness), require great effort and calculation time, which makes them unsuitable for serial applications. Therefore, in this paper, an approach for the efficient creation of simplified TT concept designs is presented. By combining simplified models for structural design and cost estimation, the most promising concepts, regarding the cost, weight, and stiffness of TT parts, can be identified. By performing a parameter study, the cost, weight, and stiffness optima of a sample part compared to a conventional FRP component can be determined. The cost and weight were reduced by 30% for the same stiffness. Applying this approach at an early stage of product development reduces the initial complexity of the subsequent detailed engineering design, e.g., by applying methods from the state of the art.

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